linux-kernel - [PATCH v3 5/7] mm/compaction: respect compaction order when updating defer counter

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu,  3 Dec 2015 16:11:19 +0900
From:	Joonsoo Kim <js1304@...il.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Vlastimil Babka <vbabka@...e.cz>, Mel Gorman <mgorman@...e.de>,
	Rik van Riel <riel@...hat.com>,
	David Rientjes <rientjes@...gle.com>,
	Minchan Kim <minchan@...nel.org>, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, Joonsoo Kim <iamjoonsoo.kim@....com>
Subject: [PATCH v3 5/7] mm/compaction: respect compaction order when updating defer counter

It doesn't make sense that we reset defer counter
in compaction_defer_reset() when compaction request under the order of
compact_order_failed succeed. Fix it.

And, it does make sense that giving enough chance for updated failed
order compaction before deferring. Change it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@....com>
---
 mm/compaction.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index 67b8d90..1a75a6e 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -126,11 +126,14 @@ static struct page *pageblock_pfn_to_page(unsigned long start_pfn,
  */
 static void defer_compaction(struct zone *zone, int order)
 {
-	zone->compact_considered = 0;
-	zone->compact_defer_shift++;
-
-	if (order < zone->compact_order_failed)
+	if (order < zone->compact_order_failed) {
+		zone->compact_considered = 0;
+		zone->compact_defer_shift = 0;
 		zone->compact_order_failed = order;
+	} else {
+		zone->compact_considered = 0;
+		zone->compact_defer_shift++;
+	}
 
 	if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT)
 		zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT;
@@ -161,11 +164,11 @@ bool compaction_deferred(struct zone *zone, int order)
 /* Update defer tracking counters after successful compaction of given order */
 static void compaction_defer_reset(struct zone *zone, int order)
 {
-	zone->compact_considered = 0;
-	zone->compact_defer_shift = 0;
-
-	if (order >= zone->compact_order_failed)
+	if (order >= zone->compact_order_failed) {
+		zone->compact_considered = 0;
+		zone->compact_defer_shift = 0;
 		zone->compact_order_failed = order + 1;
+	}
 
 	trace_mm_compaction_defer_reset(zone, order);
 }
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/